adafruit 2.8 tft lcd touch screen shield free sample

Add some sizzle to your Arduino project with a beautiful large touchscreen display shield with built in microSD card connection and a capacitive touchscreen.

This TFT display is big (2.8" diagonal) bright (4 white-LED backlight) and colorful (18-bit 262,000 different shades)! 240x320 pixels with individual pixel control. It has way more resolution than a black and white 128x64 display. As a bonus, this display has a capacitive touchscreen attached to it already, so you can detect finger presses anywhere on the screen.

This shield is the capacitive version. This touchscreen doesn"t require pressing down on the screen with a stylus, and has a nice glossy glass cover. It is a single-touch display.

This shield uses SPI for the display and SD card and is easier to use with UNO, Mega & Leonardo Arduino"s. The capacitive touchscreen controller uses I2C but you can share the I2C bus with other I2C devices.

The shield is fully assembled, tested and ready to go. No wiring, no soldering! Simply plug it in and load up our library - you"ll have it running in under 10 minutes! Works best with any classic Arduino (UNO/Duemilanove/Diecimila). Solder three jumpers and you can use it at full speed on a Leonardo or Mega as well.

This display shield has a controller built into it with RAM buffering, so that almost no work is done by the microcontroller. This shield needs fewer pins than our v1 shield, so you can connect more sensors, buttons and LEDs: 5 SPI pins for the display, 2 shared I2C pins for the touchscreen controller and another pin for uSD card if you want to read images off of it.

The display uses digital pins 13-9. Touchscreen controller requires I2C pins SDA and SCL. microSD pin requires digital #4. That means you can use digital pins 2, 3, 5, 6, 7, 8 and analog 0-5. Pin 4 is available if not using the microSD

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Today, you will learn how you can create and use buttons in your Arduino TFT Touchscreen projects.I"m using Kuman"s 2.8" TFT Shield combined with Kuman"s Arduino UNO. Bonus: The TFT Shield from Kuman comes with a free Stylus which you can use for more precise presses!

Clip in the shield onto your Arduino board. Make sure it"s not in the wrong way!You can use the pictures above for reference. Plug in your Arduino board to your PC and hop into the Arduino Software.

For the example that I"ve prepared, you can use the code that you can find here. I"ve added some comments, to make things more clear. After uploading, you can check if the display is working correctly by pressing the button. If so, the screen will change and a text will appear.

If your presses remain unrecognized, you can calibrate the display by changing the values at the top of the code (TS_MINX, TS_MAXX, TS_MINY and TS_MAXY). The button works by checking where the screen is being pressed and if it"s inside the coordinates of the button itself, a click is registered. If the above-mentioned values are not correct, the click-registering will be off

I tried it with your sketch, but it did not work firstly. However I fixed some part of the sketch, it worked. "tft.begin(0x9325);" to " tft.begin(0x9341);"0

After a while I tested another screen we bought. This worked like a charm so I think you were right and our previous screen didn’t work with SPI. I will try to read a bit more about that.

I tested the example provided by the library and it works but I tried to refresh just a part of the screen (my first tried was refreshing the whole screen for each change but it seems to be a bit difficult for me to do that.

I am trying to follow the instructions provided by the vendor https://learn.adafruit.com/2-8-tft-touch-shield/touchscreen-paint-example to no avail. Specifically:

In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.

For this tutorial I composed three examples. The first example is distance measurement using ultrasonic sensor. The output from the sensor, or the distance is printed on the screen and using the touch screen we can select the units, either centimeters or inches.

The third example is a game. Actually it’s a replica of the popular Flappy Bird game for smartphones. We can play the game using the push button or even using the touch screen itself.

As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.

Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.

I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.

After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.

Next we need to define the fonts that are coming with the libraries and also define some variables needed for the program. In the setup section we need to initiate the screen and the touch, define the pin modes for the connected sensor, the led and the button, and initially call the drawHomeSreen() custom function, which will draw the home screen of the program.

So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels  down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.

Now we need to make the buttons functional so that when we press them they would send us to the appropriate example. In the setup section we set the character ‘0’ to the currentPage variable, which will indicate that we are at the home screen. So if that’s true, and if we press on the screen this if statement would become true and using these lines here we will get the X and Y coordinates where the screen has been pressed. If that’s the area that covers the first button we will call the drawDistanceSensor() custom function which will activate the distance sensor example. Also we will set the character ‘1’ to the variable currentPage which will indicate that we are at the first example. The drawFrame() custom function is used for highlighting the button when it’s pressed. The same procedure goes for the two other buttons.

So the drawDistanceSensor() custom function needs to be called only once when the button is pressed in order to draw all the graphics of this example in similar way as we described for the home screen. However, the getDistance() custom function needs to be called repeatedly in order to print the latest results of the distance measured by the sensor.

Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.